January 25, 2022
Okay, so we’ve tried a bout of physical therapy after having a diagnosis of knee osteoarthritis (OA). Although patients can improve their function significantly with guided exercise and overall improvements in health, PT doesn’t help for everyone with complete resolution of symptoms. When is it time to consider referring to an orthopedic specialist for a knee replacement? Below are some considerations:
-Failure of conservative care (physical therapy) after 6-12 weeks of sustained effort.
-Failure of other conservative interventions such as cortisone injections, medication to reduce swelling and inflammation, or joint lubrication injections.
-Moderate to severe knee pain at rest.
-Severe pain and stiffness that limits the ability to engage in activities of daily living (ADLs) such as walking, stair climbing, getting up from a chair, and other life activities we enjoy.
-Major structural abnormalities such as bowing in (valgus) of the knee or bowing out (varus). (See picture below).
Photo courtesy of Select Flex https://selectflex.com/blogs/how-to-tips/guide-to-valgus-knee-prevention
Total Knee Arthroplasties (TKA) are becoming an increasingly more common surgical intervention in the treatment of patients with osteoarthritis of the knee. In 2017 alone over 750,000 total knee arthroplasties were performed. What exactly occurs when a TKA is done?
Steps during a TKA:
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First there will be an incision (cut) made over the knee joint starting just above the patella (knee cap) and down to the tibia (shin bone). This cut will be made on the inside of your knee (medially).
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Next the femur (the top bone of the knee) will be shaved down and shaped to fit the component (part of the replacement) that will be inserted.
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The same will happen to the tibia (the bottom bone of the knee). The tibia component will also have a plastic component, called a spacer, on top of the metal tray component. The spacer allows for a smooth, gliding surface for the knee to bend and extend upon. Should the spacer wear out, the component can be replaced, while keeping the rest of the replacement intact.
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The trial components are put in place (on the femur and tibia), while the appropriate implant is confirmed.
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After the confirmation of the appropriate components and implants, the knee is then assessed for alignment, stability, and range of motion.
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The knee cap (patella) is then prepared by shaving the back side as it is fitted with a patella trial.
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The trial components of the femur, tibia, and patella are removed.
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The final femoral, tibial, and patellar components are implanted.
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An x-ray will be taken to ensure the structure of the knee is sound.
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The procedure is finished with the surgeon closing the incision.
For a general outline of what the operation looks like, see the graphic provided below:
Photo courtesy of Physio Knowledge BD. http://physioknowledgebd.blogspot.com/2016/03/total-knee-htmlreplacement-rehabilitation.
Below is what the finished knee replacement would look like.
Photo courtesy of Dr. Murkhi’s Raj Hospital https://drmukhirajhospital.com/product/revision-total-knee-replacement/
If you are a more visual learner, here is a brief, general video courtesy of the University of Vermont Medical Center:
Now that the surgery is over and you have been discharged home, outpatient physical therapy is an essential part of the post-surgical rehabilitation process. The goal of therapy is to assist with the return of typical ranges of motion and strength, while simultaneously managing the patient’s symptoms. Later goals include restoring and expanding upon the patient’s prior level of functioning and successfully aiding them back to activities they enjoy. As with anything in physical therapy, setting expectations with patients of where they should be on a general timeline can be helpful on their journey. This gives the patient peace of mind and landmarks to look out for. There can be many imbalances remining in the body following surgery, and physical therapy helps to identify and rehabilitate them.
If you have any questions regarding your knee pain and would like to consult a health professional, give physical therapy a try by scheduling an evaluation at Portland Physical Therapy at (207)-828-4455.
Citations
Total knee replacement - orthoinfo - aaos. OrthoInfo. https://orthoinfo.aaos.org/en/treatment/total-knee-replacement/. Accessed January 5, 2022.
Total Knee Replacement Surgery (Arthroplasty) - University of Vermont Medical Center, Vermont. YouTube; 2010. https://www.youtube.com/watch?v=yCIr8q2oxtI. Accessed January 5, 2022.
Author: Brandon Drinan, PT, DPT, CSCS
